The role of fluid dynamics simulation in the design and development of various products has recently undergone what is arguably a paradigm shift due to the ability to simulate unusually complicated, multi-component, hydraulics flow circuits using three dimensional (3D) computational fluid dynamics (CFD) models. The example shows a lubrication system model (developed using the Simerics-Sys / PumpLinx CFD software) for a 16 cylinder reciprocating internal combustion engine. This represents an advance in system-level modeling of hydraulic fluid networks over the current state of the art which is a blend of zero and one-dimensional models. This also represents continued progress in the role of CFD from the traditional component level modeling to system level modeling. System level modeling provides insight into interactions between components. Finally, it is equally important that model setup and run times are reasonable relative to development time scales.